The present invention relates to the general field of the control devices of electric radiators installed in a ventilation, heating and/or air-conditioning system used in the automobile sector.
Such electric radiators are installed in the ventilation, heating and/or air-conditioning systems of the automobile sector to ensure the rapid heating of the passenger compartment at the start of operation of the vehicle with heat engine and before the heat from the engine itself ensures such heating. For an electric vehicle, such electric radiators ensure the main heating of the passenger compartment, in combination or not with a heat pump.
The invention applies to the general design of such electric radiators and the control thereof.
Conventionally, the electric radiator control device comprises at least two electronic modules each including a computer. A first module, called control module, is suitable for sending operating commands to the electric radiator and the second module, called management module, implemented within the electric radiator, is suitable for managing the operation of the electric radiator according to the commands received from the control module.
To control the electric radiator, it is therefore necessary for the control module to be able to send to a management module command signals to control the operation of the electric radiator. Typically, the control module sends to the computer of the management module of the electric radiator a required operating power.
In parallel, it is equally necessary, in an automobile ventilation, heating and/or air-conditioning system, for the electric radiator to be able to return to the control module diagnostic elements concerning its operation.
In particular, conventionally, the electric radiator may need to give feedback to the control module concerning the presence of any short-circuits, the presence of an electrical supply shortage or of an overvoltage on its power supply. It may also, advantageously, need to send information on the presence of an overheating condition or of an overshoot of a given temperature.
Currently, between the computers of such modules, it is known practice to use a bus of the LIN or CAN type which allows two-way communications between a plurality of computers. However, this is proving to be a costly solution. If no other use of the bus is envisaged, such a cost is not justified.
Other communication systems between two computers, used in such modules, use two communication wires, one from the control module to the management module and another from the management module to the control module. The two modules can thus dialog with one another.
The latter implementation entails installing two communication wires, which increases the complexity of the construction and adds to the cost compared to the installation of a one-way communication.